Thin phase-separation

Overney R M, Meyer E, Frommer J, Brodbeck D, Luthi R, Flowald L, Guntherodt Fl-J, Fu]ihara M, Takano FI and Gotoh Y 1992 Friction measurements of phase separated thin films with a modified atomic force microscope Nature... 

Another kinetic jjhenomenon where Calm s critical waves can possibly be visualized and studied is the replication of interphase boundaries (IPB) illustrated in Figs. 8-10. Similarly to the replication of APBs. it can arise after a two-step quench of an initially uniform disordered alloy. First the alloy is quenched and annealed at temperature T in some two-phase state that can be either metastable or spinodally unstable with respect to phase separation. Varying the annealing time one can grow here precipitates ("droplets ) of a suitable size /. For sufficiently large /, the concentration c(r) within A-riched droplets is close to the equilibrium binodal value C(,(T ) (thin curve in Fig. 9). 

Figure 12.4 AFM images of thin PS-fo-P4VP (162 400 87 400) films (3-pentanone solvent) with phase separation structures of P4VP cylinders in PS matrices on glass substrates, and height profiles of horizontal lines in these images, (a), (d) Before and (b), (e) after immersion in methanol (c), (f) after being doped with TCPP (d)-(f) are the height profiles ofthe horizontal lines shown in the AFM images...

Kanemoto, R., Anas, A., Matsumoto, Y, Ueji, R., Itoh, T., Baha, Y, Nakanishi, S Ishikawa, M. and Biju, V. (2008) Relations Between dewetting of polymer thin films and phase-separation of encompassed quantum dots. J. Phys. Chem. C, 112, 8184-8191. 

The computation of the curvatures from the bulk field differential geometry has proven to be rather imprecise. The errors produced by the use of the approximate formulas (100)-(104) are especially big if the spatial derivatives of the field sharp peaks at the phase interface. This is a common situation in the late-stage kinetics of the phase separating/ordering process, when the order parameter is saturated and the domains are separated by thin walls. Here, to calculate the curvatures, we propose a much more accurate method. It is based on the observation that the local curvatures are quantities that can be inferred solely from the shape of the interface, without appealing to the properties of the bulk field [Pg.212]

Dimitrios Maroudas, Modeling of Radical-Surface Interactions in the Plasma-Enhanced Chemical Vapor Deposition of Silicon Thin Films Sanat Kumar, M. Antonio Floriano, and Athanassiors Z. Panagiotopoulos, Nanostructured Formation and Phase Separation in Surfactant Solutions Stanley I. Sandler, Amadeu K. Sum, and Shiang-Tai Lin, Some Chemical Engineering Applications of Quantum Chemical Calculations... 

The next three chapters (Chapters 9-11) focus on the deposition of nano-structured or microstructured films and entities. Porous oxide thin films are, for example, of great interest due to potential application of these films as low-K dielectrics and in sensors, selective membranes, and photovoltaic applications. One of the key challenges in this area is the problem of controlling, ordering, and combining pore structure over different length scales. Chapter 9 provides an introduction and discussion of evaporation-induced self-assembly (EISA), a method that combines sol-gel synthesis with self-assembly and phase separation to produce films with a tailored pore structure. Chapter 10 describes how nanomaterials can be used as soluble precursors for the preparation of extended... 

In physics, an elastic two-dimensional plate is tenned a membrane (Latin membram = parchment) but in chemistry the tenn denotes a body, usually thin, which serves as a phase separating two other bulk phases. If this body is penneable to the same degree for all components of the adjacent phases and does not affect their mobility, then its only function is to prevent rapid mixing of the two phases. This is then tenned a diaphragm. A real membrane must exhibit a certain selectivity, based on different penneability for the components of the two phases, and is then tenned a semipenneable membrane. Membranes separating two electrolytes that are not penneable to the same degree for all ions are called electrochemical membranes. It is with these that we are concerned here. 

Phase separation controlled by diffusion exchange often results in a skin which is composed of a micellar assembly of nodules, as will be discussed below. When extremely hydrophobic polymers (e.g., modifled-PPO) are cast from dioxane into water (pg = p = p ) a dense polymer layer is formed at the solution s interface that somewhat resembles the type of layer formed by Interfacial polymerization. There is almost no inward contraction of the interfacial skin, and the coagulation process is controlled by diffusion through the dense, interfacial thin film. These result in an anisotropic membrane with a very fine "coral" structure (Figures 9 and 10). 

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